Optical system

Abstract

An anti-shake compensation structure is provided. The anti-shake compensation structure includes an auto-focus module driving a lens to move along a light entering path of the lens. The auto-focus module includes a lens holder holding the lens, a coil adjacent to the lens holder, and a magnet corresponding to the coil. The anti-shake compensation structure further includes an outer frame supporting the lens holder, and a compensation driving unit driving the lens to sway relative to the outer frame along a direction not parallel to the light entering path. The compensation driving unit includes a compensation coil corresponding to the magnet.

What is claimed is: 
     
         1 . An optical system, comprising:
 a first movable portion, connected to a lens;   a fixed portion, wherein the first movable portion is moveable;   a second movable portion, connected to an image sensor, and the second movable portion is movable relative to the first movable portion;   a driving assembly, driving the first movable portion to move, wherein the driving assembly comprises:
 a magnet; 
 a first coil, corresponding to the magnet and generating a first driving force to drive the first movable portion; 
 a second coil, corresponding to the magnet and generating a second driving force to drive the second movable portion, 
   wherein a first surface and a second surface of the magnet face the first coil and the second coil respectively, and the first surface and second surface face different direction.   
     
     
         2 . The optical system as claimed in  claim 1 , wherein the fixed portion comprises a base adjacent to a bottom plate that supports the image sensor.
 wherein the base has a plate-like shape and is perpendicular to a light entering path.   
     
     
         3 . The optical system as claimed in  claim 2 , wherein a gap is provided between the bottom plate and the base, so that the bottom plate is movable relative to the base. 
     
     
         4 . The optical system as claimed in  claim 2 , wherein the base does not have a through hole that is corresponding to the light entering path. 
     
     
         5 . The optical system as claimed in  claim 2 , wherein the bottom plate has a plate-like shape and is perpendicular to the light entering path. 
     
     
         6 . The optical system as claimed in  claim 2 , wherein the bottom plate is located between the image sensor and the base when viewed along the direction that is perpendicular to the light entering path. 
     
     
         7 . The optical system as claimed in  claim 2 , further comprising a suspension element, wherein the first movable portion and the second movable portion are movably connected to the fixed portion via the suspension element, and the bottom plate is located between a portion of the suspension element that is in direct contact with the fixed portion and the base when viewed along a direction that is perpendicular to the light entering path. 
     
     
         8 . The optical system as claimed in  claim 2 , further comprising a suspension element, wherein the first movable portion and the second movable portion are movably connected to the fixed portion via the suspension element, and the bottom plate is located between a portion of the suspension element that is in direct contact with the first movable portion and the second movable portion and the base when viewed along a direction that is perpendicular to the light entering path. 
     
     
         9 . The optical system as claimed in  claim 2 , further comprising a suspension element, wherein the first movable portion and the second movable portion are movably connected to the fixed portion via the suspension element. 
     
     
         10 . The optical system as claimed in  claim 9 , wherein the bottom plate is located between the suspension element and the base when viewed along a direction that is perpendicular to the light entering path. 
     
     
         11 . The optical system as claimed in  claim 2 , further comprising a position sensing element, sensing the movement of the first movable portion and the second movable portion relative to the fixed portion, wherein the position sensing element does not overlap the image sensor when viewed along the light entering path. 
     
     
         12 . The optical system as claimed in  claim 11 , wherein the position sensing element at least partially overlaps the second movable portion when viewed along the light entering path. 
     
     
         13 . The optical system as claimed in  claim 11 , wherein the lens is corresponding to the image sensor, wherein the lens is movable relative to the image sensor and the fixed portion. 
     
     
         14 . The optical system as claimed in  claim 13 , further comprising a focus driving assembly, driving the lens to move relative to the image sensor along the light entering path. 
     
     
         15 . The optical system as claimed in  claim 14 , wherein the focus driving assembly at least partially overlaps the bottom plate when viewed along the light entering path. 
     
     
         16 . The optical system as claimed in  claim 14 , wherein the focus driving assembly at least partially overlaps the position sensing element when viewed along the light entering path. 
     
     
         17 . The optical system as claimed in  claim 14 , wherein the second movable portion is at least partially located between the image sensor and the base when viewed along the direction that is perpendicular to the light entering path. 
     
     
         18 . The optical system as claimed in  claim 14 , wherein the image sensor is at least partially located between the second moveable portion and the position sensing element when viewed along the direction that is perpendicular to the light entering path. 
     
     
         19 . The optical system as claimed in  claim 14 , wherein the position sensing element is at least partially located between the image sensor and the base when viewed along the direction that is perpendicular to the light entering path. 
     
     
         20 . The optical system as claimed in  claim 1 , wherein the lens corresponds to the image sensor, the first movable portion and the second movable portion bring the lens and the image sensor to move relative to the fixed portion when the first movable portion and the second movable portion moves relative to the fixed portion.